scsi: smartpqi: add counter for parity write stream requests

scsi: smartpqi: add counter for parity write stream requests

Add sysfs entry to check for write stream requests.

Move existing raid_bypass_cnt into a structure named pqi_raid_io_stats and
add member write_stream_cnt. These two counters are related because write
stream detection is only checked if an I/O request is eligible for bypass
(AIO).

Example usage:

lsscsi
[15:1:0:0]   disk    Adaptec  LOGICAL VOLUME   0129  /dev/sdae

cat /sys/block/sdae/device/ssd_smart_path_enabled
1
^
|
+---- NOTE: here bypass has been enabled on device sdae

To read the counter for parity write stream requests:

cat /sys/block/sdae/device/write_stream_cnt
0x60cd507

Reviewed-by: Scott Benesh <scott.benesh@microchip.com>
Reviewed-by: Mike McGowen <mike.mcgowen@microchip.com>
Signed-off-by: Mahesh Rajashekhara <mahesh.rajashekhara@microchip.com>
Co-developed-by: Kevin Barnett <kevin.barnett@microchip.com>
Signed-off-by: Kevin Barnett <kevin.barnett@microchip.com>
Signed-off-by: Don Brace <don.brace@microchip.com>
Link: https://lore.kernel.org/r/20240827185501.692804-4-don.brace@microchip.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>